Data Pioneer Donald Davies Dies

Wednesday 31 May 2000, LONDON (AP) - Donald W. Davies, whose pioneering work on data transmission contributed to the development of the Internet, has died at 75.

Davies died Sunday, his family said. The cause of death was not announced. Working at the National Physical Laboratory, Davies is credited with coining the term "packet switching'' in 1966 for data transmission that is fundamental to the workings of the Internet. He also led a team that built one of the first functioning networks using packet data.

In an article for The Guardian newspaper in 1997, Davies said he had realized that it was inefficient for a computer to send an entire file to another computer in an uninterrupted stream of data, "chiefly because computer traffic is 'bursty' with long periods of silence.''

"So, in November 1965, I conceived the use of a purpose-designed network employing packet switching in which the stream of bits is broken up into short messages, or 'packets,' that find their way individually to the destination, where they are reassembled into the original stream,'' Davies wrote.

Other scientists also came to the same conclusion at about the same time.

But Davies' team presented its paper at a 1967 conference in Tennessee where Lawrence Roberts of the Advanced Research Projects Agency of the U.S. Department of Defense presented a design for creating a computer network. In the United States, this led to the development of ARPANET, the prototype for the Internet.

Davies' team "explored packet switching in their laboratory, but Donald could not convince the British to fund a wide area network experiment. His papers, however, did show the importance of packet switching for computer communication,'' Roberts commented in his chronology of the Internet's development.

Davies' later work concentrated on the security of data. He undertook security studies for teleprocessing systems, financial institutions, government agencies and suppliers.

Davies received the British Computer Society Award in 1974.

His books included "Communication Networks for Computers'' in 1973, "Computer Networks and their Protocols'' in 1979, and "Security for Computer Networks'' in 1984. Davies is survived by his wife, Diane, their two sons and a daughter. Funeral arrangements were not announced.